This application claims priority to Japanese Patent Application 8-128570 filed May 23, 1996, Japanese Patent Application 8-259829 filed Sep. 30, 1996, Japanese Patent Application 8-259831 filed Sep. 30, 1996, Japanese Patent Application 8-303322 filed Nov. 14, 1996, Japanese Patent Application 8-306829 filed Nov. 18, 1996, Japanese Patent Application 8-324430 filed Dec. 4, 1996, and Japanese Patent Application 8-349119 filed Dec. 26, 1996, all of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a contact probe used as a probe pin, or a socket pin etc., for electrical testing of devices, such as semiconductor IC (Integrated Circuit) chips, liquid crystal devices, etc., and more particularly to a contact probe integrated into a probe card, a probe device, a test socket, etc. and which are brought into contact with respective terminals of a device under test.
2. Description of Related Art
Contact pins are generally used for carrying out an electrical testing by being brought into contact with respective terminals of a device under test, for example, such as a semiconductor chip, such as an IC chip, an LSI (Large Scale Integrated Circuit) chip, an LCD (Liquid Crystal Display), etc.
In recent years, with high integration and miniaturization of devices, such as IC chips etc., contact pads configured as electrodes formed with a narrow pitch, multi pins, and narrow pitch contact pins have been required. According to one solution to the above requirements, a contact probe made of tungsten needles used as contact pins has been proposed. However; with this solution it is difficult to deal with multi pins and narrow pitch requirements due to a limitation in the diameter of the tungsten needles.
In Japanese Examined Patent Publication No. JP-B-7-82027, a contact probe technology where a plurality of wiring patterns are formed on a resin film and respective front end portions of the wiring patterns are arranged to project from the resin film to form contact pins is proposed. According to this technology, a probe device having multi pins and narrow pitch is possible and numerous complex parts are not required as compared to other technologies. As shown in FIG. 110, a conventional contact probe 1A has a structure where wiring patterns 3A formed from Ni (nickel) or a Ni alloy are attached on one face of a polyimide resin film 2A and front end portions of the wiring patterns 3A are projected from an end portion of the resin film 2A so as to form contact pins 3aA. In FIG. 110, positioning holes 4A are formed in the polyimide resin film 2A as will be described later.
Japanese Unexamined Patent Publication No. JP-A-6-324081 proposes a probe device (probe card) using contact probes having a flexible substrate, as in the previously discussed publication, where front end portions of wiring patterns constitute contact pins. According to this probe device, a matching is conducted with respect to a difference in pin pitches of an IC chip or device under test, etc. and a tester. The proposed probe device is suitable for probe testing an IC chip etc. having multi pins and narrow pitch.
FIGS. 111-113 will now be used to explain the operation of a conventional probe device 11A where a contact probe 1A is integrated with a mechanical parts 10A. The mechanical parts 10A include a mounting base 12A, a top clamp 13A and a bottom clamp 14A. The probe device 11A includes the top clamp 13A securing a printed circuit board 15A, the mounting base 12A, and the contact probe 1A via a bottom clamp 14A. The bottom clamp 14A is attached to the top clamp 13A by bolts 17A and bolt holes 16A. The contact probe 1A having wiring patterns 3A (FIG. 110) is pressed by the bottom clamp 14A, so that the wiring patterns 3A press against an IC chip under test while being maintained in a constant inclined state.
FIG. 112 illustrates the probe device 11A of FIG. 111 after assembly. FIG. 113 is a sectional view taken along a line Exe2x80x94E of FIG. 112. As shown in FIG. 113, the front ends of the wiring patterns 3A are brought into contact with an IC chip I by the mounting base 12A. The mounting base 12A is provided with positioning pins 18A for adjusting the position of the contact probe 1A, and the wiring patterns 3A. Thus, the IC chip I can be accurately positioned by inserting the positioning pins 18A into the positioning holes 4A of the contact probe 1A. Elastic bodies 20A of the bottom clamp 14A are pressed against portions of the wiring patterns 3A at windows 19A provided in the contact probe 1A. In this way, the wiring patterns 3A at the windows 19A are brought into contact with electrodes 21A of the printed circuit board 15A forming a signal path by which signals obtained from the wiring patterns 3A can be transmitted via the electrodes 21A of the printed circuit board 15A.
However, the above-described conventional contact probe 1A has the following problems. As shown in FIG. 114, the contact pins 3aA of the conventional contact probe 1A are attached on one face of the resin film 2A. However, the resin film 2A is fabricated from, for example, polyimide resin and therefore, the resin may be elongated by absorbed moisture changing an interval t between the contact pins 3aA. Accordingly, the contact pins 3aA may not accurately contact pads of an IC chip, or device under test, etc. and therefore, an accurate electrical test cannot be conducted. Furthermore, although the positioning holes 4A for integrating the contact probes 1A to the probe device 11A are provided in the resin film 2A of the contact probe 1A, the resin film 2A has a small hardness value and accordingly, the positioning holes 4A are susceptible to being deformed. Therefore, accurate positioning of the contact probe 1A cannot be performed.
Furthermore, according to the contact probe 1A (FIGS. 110-113), during testing of a device, an amount of pressure applied to contact pins of the contact probe is increased or decreased to provide a desired contact pressure. A large amount of pressure must be applied to the contact pins in order to provide a large contact pressure. However, according to the first type of contact probe, front end portions of wiring patterns of the contact probe are used to form the contact pins. The contact pins are made from a material such as Ni (nickel). Therefore, a hardness of the contact pins is typically about Hv 300. Due to the low hardness of the contact pins 3aA, the contact pins may be bent or deformed under excessive contact pressure. Accordingly, there is a limited amount of pressure that can be exerted on the contact pins so that a large contact pressure cannot be obtained. Therefore, a sufficient contact pressure cannot be obtained during electrical measurements of a device under test, resulting in contact failure.
To solve the above problem, there is provided a means of adding an additive agent, such as saccharin etc. in the Ni plating of the contact pins. Although at normal temperature the contact pins have a hardness of Hv 350 or more, the hardness of the contact pins drops rapidly to Hv 200 or less when the contact pins are heated to a high temperatures (e.g., 300xc2x0 C.). This is due to the S (sulphur) content of the additive agent, such as saccharin etc. which reduces the contact pin hardness at high temperatures. Therefore, the above-described contact probe cannot typically be used at high temperatures, particularly when the contact probe is used as a chip carrier for a burn-in test, etc. which subjects the contact probe to high temperatures.
In addition, surfaces of respective terminals (pads) of an IC chip, etc. are typically made from a material, such as an Al (aluminum) alloy, etc. When such terminals are exposed to air, oxidation occurs and the terminals have a thin aluminum oxide film formed thereon. Therefore, during electrical testing, the aluminum oxide film formed on the surface of the pads of an IC chip, etc. must be removed in order to expose an aluminum matrix underneath the surface so as to ensure proper electrical conductivity between the pads and the contact pins. Accordingly, the contact pins of a contact probe are overdriven while being brought into contact with the surfaces of the pads (e.g., the contact pins are pulled across the pads during contact) so that the aluminum oxide film on the surfaces of the pads is scrubbed off by front end portions of the contact pins exposing the internal aluminum matrix of the pads. The above-described operation is referred to as scrubbing and is important for ensuring proper contact between the contact pins and the pads of the IC chip, etc. during electrical testing thereof.
In performing the scrubbing operation, it is necessary to prevent the contact pins from damaging the aluminum matrix underneath the aluminum oxide film on the surfaces of the pads. Accordingly, in fabricating the contact pins, a mask exposure technology is used and the front end portions of the contact pins are formed having circular arc (convex) faces in a plane view. This is due to the fact that it is difficult to form a fine pattern on a mask in accordance with a desired shape (see FIG. 110). In contrast, a conventional tungsten needle has a planer front end face due to a polishing operation which is performed on the front end portions of the needles in order to adjust the lengths of the respective needles. However, the above-described contact pins are provided with a convex circular face resulting in a small contact area with the pad of the IC chip, etc. so that the contact pins exert a large contact pressure on the pad due to the small contact area. Accordingly, the contact pins are liable to scrape off the aluminum matrix of the pad during the scrubbing operation as compared with the conventional tungsten needle contact probe.
Therefore, it is necessary to ensure a large enough contact angle of the contact pin with respect to the pad so that the aluminum matrix of the pad is not damaged during the scrubbing operation. This is due to the fact that when the contact angle is small, an amount of removed aluminum at the surface of the pad can significantly increase resulting in damage to the aluminum matrix of the pad. However, contact pins 3aA which are formed from a resin film 2A project along a face of the resin film 2A and the contact angle of the contact pin cannot be greater than the angle of the face of the resin film 2A (see FIG. 110). In other words, the angles of the contact pins 3aA are restricted by the angle of the face of the resin film 2A. Therefore, the angles of the contact pins 3aA cannot be set independently from the surface of the resin film 2A.
In the contact probe described above, it is possible to increase the contact angle of the contact pins by increasing the angle of the face of the resin film by devising a way of integrating the contact probe in a probe card which sets the angle of the resin film and the contact pins. In such a case, the scrubbing distance (i.e., length for scrubbing off a skin along the surface of the pad) is extended and depending on a magnitude of the contact angle since the contact angle determines how far the front end portions of the contact pins project over the pads during the scrubbing operation. For example, in the case of a pad having a substantially square form in a plane view with a sides of approximately 90 xcexcm to 100 xcexcm in length, when the scrubbing distance is set to 8 xcexcm with an amount of overdriving of 75 xcexcm and a contact angle of 15xc2x0 to 20xc2x0, even with a slight increase in the contact angle of 5xc2x0, the scrubbing distance becomes 12 xcexcm or more.
Furthermore, when the angle of the face of the resin film is increased as described above, the resin film is raised with respect to the contact face by an amount of the angle. In such a case, the resin film and contact probe constitute a probe device which is integrated with various mechanical parts to form a probe card (or prober). When the angle of the resin film is increased, the height dimension of the probe device also increase. However, the above-described probe device is mounted in a prober and the prober cannot be typically made so that it is of a variable height (i.e., a distance/height from the IC chip etc.). Therefore, when the height of the probe device exceeds a predetermined level, the probe device cannot be mounted in the prober.
However, the following problems remain in the above-described contact probe and probe device including the contact probe (contact probe 1A, FIGS. 110-113). Connection from electrodes of the IC chip I to the electrodes 21A of the printed circuit board 15A is conducted via the wiring patterns 3A integrated on the resin film 2A. Therefore, there is no degree of freedom in the pad arrangement of the electrodes 21A on the side of the printed wiring board 15A. Although no particular problem is caused in the case where the electrodes of the IC chip I are arranged uniformly at four sides thereof, it is difficult to deal with the case where the electrodes are arranged nonuniformly on the four sides. In other words, in the case where the electrodes are concentrated on one side of the IC chip, for example, in the case of a driver IC of an LCD, etc. (i.e., several hundreds pins are formed on the longer side of a 3 mmxc3x971 mm size chip), there is no space for arranging pads of the electrodes 21A on the printed circuit board 15A. Therefore, it is difficult to connect the electrodes of the IC chip I to the printed wiring board 15A.
According to the previously described contact probe 1A, one side of the contact probe is typically arranged to align with the pad positions of an IC chip, etc., while the other side is connected to the printed wiring board 15A. In order to widen the pitch of the wiring patterns 3A of the contact probe 1A, the contact probe 1A is formed in a trapezoidal shape (see FIGS. 110-113). Furthermore, positioning holes 4A are provided in the contact probe 1A and the contact probe 1A is integrated with highly accurately fabricated mechanical parts by using the positioning holes 4A. In this way the mechanical parts are integrated with the printed wiring board 15A. In addition, according to the contact probe 1A, a photolithography technology capable of finely forming patterns is used for a fabricating and forming process of the wiring pattern 3A. Therefore, the contact probe 1A, advantageously, provides a narrowed pitch front end portion so that the contact probe 1A can be brought into contact with the narrow pitch of the contact pads of a device under test.
However, the accuracy of positioning the contact pins 3aA of the contact probe 1A with respect to the contact pads of an IC or an LCD, is dependent upon the accuracy of the fixing means with respect to the mechanical parts. In other words, the accuracy of fasteners using the positioning holes 4A. Accordingly, even if the pitch of the contact pins 3aA is narrowed or the diameter of the front end of each of the contact pins 3aA is considerably diminished, when the accuracy of positioning is poor, it is difficult to take advantage of the advantages of the contact probe 1A.
Furthermore, there are the following additional problems in the contact probe 1A. According to the contact probe 1A, the front end is provided with a portion where the pitch of the wiring patterns 3A is narrowed. Therefore, the yield is lowered in the photolithography or plating step, etc. used in fabricating the contact probe 1A due to the narrow pitch area. This means that in fabricating the contact probe 1A, the yield of the contact probe 1A is governed by the yield of the portion where the pitch is narrowed. In this case, the contact probe 1A is formed in a trapezoidal shape with the narrower front end portion having the narrower pitch wiring patterns 3A and the wider rear end portion having wiring patterns 3A that are coarse. Moreover, in integrating the contact probe 1A to the printed wiring board 15A, a considerably large area is required to accommodate the contact probe 1A. In this case, a necessity of a large area for the contact probe 1A results in a small number of the contact probes 1A being able to be formed from a resin film 2A used as a raw material and having limited area. Therefore, when the above-described contact probe 1A is fabricated, the yield is governed by the front end portion having the narrow area with the narrow pitch wiring, while the area per se of the contact probe is governed by the wider portion with the coarse pitch wiring.
Furthermore, in relation to the above-described problems, the front end portion or contact pin of the contact probe 1A is liable to be destroyed since the contact pins project from the resin film 2A. In this case, the entire contact probe 1A must be replaced even if only one contact pin is damaged. Accordingly, maintenance costs of a probe device using the contact probe 1A increase. Furthermore, the above-described contact probe 1A does not allow for ease of changing contact pressure of the contact pins.
A conventional probe card is shown in FIG. 116. According to the probe card, perforated portions are provided at measurement positions of the card comprising a glass epoxy plate with contact pins (needles) projecting from the measurement positions. A material, such as W (tungsten) having a small degree of wear is generally used as the material for fabricating the needle. The probe card is provided in a shape of a leaf spring where the contact pins are extended toward a direction inclined downwardly and is referred to as a horizontal arranged needle type probe card. In addition, as illustrated by FIGS. 115(a) and 115(b), terminals to be inspected by the probe card are peripherally arranged, wherein terminal electrodes are formed only at a periphery of a chip (FIG. 115(a)), and planarily arranged, wherein terminal electrodes are formed over the entire face of the chip (FIG. 115(b)). In this case, although the above-described horizontal arranged needle type probe card can deal with the peripherally arranged terminals, it cannot deal with the planarly arranged terminals. Furthermore, there is a limitation in multi pin formation of the probe card. In addition, according to the horizontal needle arranged type probe card, the total length of the contact pin is typically 40 mm to 30 mm. Therefore, there is a limitation in an inspection speed using the probe card. Hence, a vertically arranged probe card was devised as shown in FIG. 117 to overcome the deficiencies of the above-described horizontally arranged needle type contact probe. According to the vertically arranged type probe card, the card can deal with the planarly arranged terminals, multi pin formation can be realized, and the problem of the inspection speed is also improved since the length of the contact pin is approximately 11 mm to 7.5 mm which is comparatively short.
However, the vertically arranged type probe cards have the following problems. When there is a more or less a deviation with the respective total lengths of the contact pins, if all of the contact pins including contact pins of various lengths are brought into contact with respective terminals, the longer contact pins are bent during an overdriving operation (i.e., contact pins are pulled down further than from where they are brought into contact with the terminals). According to the above-described probe card, the material of the contact pins is tungsten which is highly rigid. Therefore, in overdriving the contact pin, the longer contact pins are not sufficiently bent and the shorter contact pins are not firmly brought into contact with the terminals. Particularly, in the case of the vertical needle type probe card, the contact pins are brought into contact with the terminals substantially in a vertical direction which makes the contact pins less likely to bend. In addition, the above-described contact pins made of tungsten are devoid of flexibility. Therefore, even if they are bent, the direction of bending does not stay constant. As a result, contiguous ones of the contact pins may erroneously be brought into contact with each other causing shorting between contact pins. Also, according to the above-described needle type contact probe, the integration of the contact pins, alignments of the heights and the positions of the respective pins must be performed manually, which is very difficult. Furthermore, it is difficult to deal with the multi pin and narrow pitch formation due to the limitation in the diameter of the tungsten needle.
Accordingly, it is an object of the present invention to provide a contact probe capable of carrying out accurate electrical tests by minimizing a change in intervals between contact pins due to a change in humidity and by firmly bringing the contact pins into contact with pads of a device under test (also referred to as object of measurement) with accurate positioning by minimizing deformation of positioning holes.
Another object of the present invention to provide a contact probe exhibiting a large amount of hardness and excellent thermal resistance during high temperature operation.
A further object of the present invention to provide a contact probe and a probe device including the contact probe which perform an adequate scrubbing operation but prevent the scrubbing distance from increasing more than is necessary and without damaging material under a film on a surface of a pad of a device under test (also referred to as an object of measurement).
An additional object of the present invention to provide a contact probe and a probe device including the contact probe allowing for multi pin and narrow pin pitch formation applicable to testing a semiconductor device, such as an IC chip, LCD, etc. having electrodes which are not arranged in uniform fashion along sides of the semiconductor device.
A still further object of the present invention to provide a contact probe having ease of positioning with respect to pads of a device under tests, such as an IC, or LCD, etc.
Yet another object of the present invention to provide a contact probe with reduced fabrication costs ease of maintenance, such as ease of replacing contact probes or changing contact pressure.
Yet a further object of the present invention to provide a contact probe and a probe device including the contact probe specified as follows:
(1) The contact probe can deal with planarly arranged terminals;
(2) The total length of the contact pin is short and the inspection speed is fast;
(3) The contact probe can deal with the multi pins and narrow pitch formation;
(4) The contact pin is flexible during an overdriving of the pin;
(5) The direction of bending the contact pin can be adjusted so as to be constant; and
(6) The contact probe exhibits excellent high frequency characteristic.
The above and other objects are achieved according to the present invention by providing by providing in a probe device, an improved contact probe including a film; a plurality of wiring patterns formed on the film, each wiring pattern having a front end portion projecting from the film so as to form contact pins; and a metal layer provided on the film.
According to the above-described probe device, the film, such as a resin film, etc. is liable to extend due to moisture absorption. Accordingly, a metal layer is provided on the film so that extension of the film is restrained by the metal layer under various humidity conditions. In other words, a small deviation in an interval between the respective contact pins occurs and the contact pins can be brought into contact with pads accurately and with fine precision. Accordingly, a proper scrubbing operation is ensured since the contact pins can brought into precise contact with pads of a device under test and the angle of the contact pin with respect to the pad does not deviate much from a desired value. Furthermore, the metal film can be used as a ground whereby a design taking an impedance matching up to the vicinity of the front end of the contact probe can be performed. In this way, adverse influences caused by reflection noise can be prevented in performing a test in a high frequency region. In other words, when the characteristic impedance between the side of the substrate wiring and the contact pins is not matched in the middle of a transmitting cable from a tester (also referred to as a prober), reflection noise results. In this case, the longer the transfer cable having different characteristic impedances, the more the reflection noise is increased. The reflection noise constitutes a signal distortion and is liable to cause erroneous operation in a high frequency region. According to the contact probe, by using the metal film as a ground, the characteristic impedance can be matched up to the vicinity of the front end of the contact pin by the side of the substrate wirings and erroneous operation caused by reflection noise can be restrained.
According to a second aspect of the present invention, there is provided the probe device of the first aspect, wherein the contact pins of the contact probe are made of a nickel-manganese alloy including manganese in a range from 0.05 wt. % to 1.5 wt. %.
According to the above-described probe device, the front end portion is made of a nickel-manganese alloy including manganese in a range of from 0.05 wt. % to 1.5 wt. %. Accordingly, the front end portion of the contact pins exhibit a hardness of Hv 350 or more even during high temperature operation (e.g., 500xc2x0 C.). In other words, the hardness of the Nixe2x80x94Mn alloy is not extremely lowered by high temperature heating. Furthermore, when the amount of manganese (Mn) is less than 0.05 wt. %, the hardness of Hv 350 or more cannot be obtained. When amount of manganese (Mn) exceeds 1.5 wt. %, the contact pins may be bend due to an increase in stresses at the front end portion thereof and the contact pins also become very brittle and toughness is lowered. Accordingly, by setting the manganese content in the above-specified range, the high hardness and toughness necessary for a contact probe can be provided.
According to a third aspect of the present invention, there is provided the probe device of the first aspect, wherein the contact pins of the contact probe are bent at a middle position thereof.
According to the above-described probe device, the contact pin is bent at the middle portion and therefore, the angle with respect to an object of measurement (pad) can be changed at the front end portion and the base end portion of the contact pin. Thereby, an angle (contact angle) of the front end portion of the contact pin with respect to the pad can be fixed to be large without enlarging an angle of the film with respect to the pad. Accordingly, a matrix of the pads can be prevented from impairing in the scrubbing operation without excessively enlarging the scrubbing distance and without enlarging the height of the probe device.
According to a fourth aspect of the present invention, there is provided the probe device of the third aspect, wherein each of the contact pins of the contact probe has a tip portion opposite an end portion, the tip portion configured such that when the tip portion is brought into contact with an object of measurement, an angle of the tip portion with respect to a contact face thereof is in a range of 60xc2x0 to 90xc2x0, and the end portion configured such that an angle of the end portion with respect to the contact face is in a range of 0xc2x0 to 30xc2x0.
According to the above-described probe device, the angle of the front end portion of the contact pin with respect to the contact face is provided to be 60xc2x0 or more. Therefore, the matrix of the pad is not damaged. In addition, the angle of the front end portion of the contact pin with respect to the contact face is set to be smaller than 90xc2x0. This is because if the angle of the front end portion is 90xc2x0 or more, the skin of the pad cannot be properly scrubbed off during the scrubbing operation and sufficient conductivity is not ensured resulting in contact failure during testing. Furthermore, the angle of the base end portion of the contact pin with respect to the contact face is set to be 30xc2x0 or less. Therefore, the scrubbing distance is not excessively prolonged and the front end of the contact pin is not projected from the pad in the scrubbing operation. In addition, the angle of the base end portion of the contact pin with respect to the contact face is fixed to be 0xc2x0 or more, because if this condition is not satisfied, a sufficient overdriving amount cannot be provided in the scrubbing operation.
Furthermore, according to the above-described probe device, a face having a parallel degree with respect to the contact face of the pad that is higher than that of the conventional contact pin, is formed at the front end portion by bending the contact pin as described above. This is required due to the following positioning operation. In positioning the contact pin with respect to the pad, a method where light is irradiated from the direction of the pad (normally, from below) toward the contact pin and light reflected from the contact pin is detected so that the position of the contact pin is recognized is used. However, according to a conventional contact pin, which is not bent, when the contact pin is integrated to a probe card, the contact pin only projects to the contact face of the pad with a low angle of, for example, about 15xc2x0 to 20xc2x0. Accordingly, even if light is irradiated from the direction of the pad, the amount of reflected light is small. Therefore, positional detection of the contact pin is difficult. In respect thereto, according to the contact pin of the present invention, a face having a high vertical degree is formed with respect to a direction in which light is irradiated. Therefore, a sufficient amount of light is reflected whereby the positional detection is facilitated.
According to a fifth aspect of the present invention, there is provided the probe device of the fourth aspect, further including a substrate attached to the contact probe, the substrate having terminals connected to respective base ends of the wiring patterns; and an inclination holding member having a lower face inclined at angle in a range of 0xc2x0 to 30xc2x0 with respect to the contact face of an object of measurement and configured to maintain the end portion so that the angle of the end portion with respect to the contact face is in the range of 0xc2x0 to 30xc2x0; wherein the contact probe is supported by the inclination holding member such that the metal layer of the film is brought into contact with the lower face of the inclination holding member.
According to the above-described probe device, the inclination holding member is installed and the lower face is gradually inclined downwardly toward the front end side by an angle in a range of 0xc2x0 to 30xc2x0 with respect to the contact face. The front end side of the film is supported by being brought into contact with the lower face. Therefore, the angle of the base end portion of the contact pin projected from the front end of the film with respect to the contact face is stably maintained to a value described in the fourth aspect of the present invention.
According to a sixth aspect of the present invention, there is provided the probe device of the first aspect, the contact probe further including a contact probe main body including a plurality of the wiring patterns disposed as main wiring patterns; and a contact probe branch portion which branches from the contact probe main body, integrally formed with the contact probe main body, and includes a plurality of the wiring patterns disposed as branch wiring patterns formed by dividing portions of the main wiring patterns.
The above-described probe device includes the contact probe main body where the main wiring patterns are formed and the contact probe branch portion that is branched from the contact probe main body and is integrally formed therewith. The contact probe branch portion is provided with the branch wiring patterns formed by branching portions of the main wiring patterns. Accordingly, the portions of the main wiring patterns are distributed to the branch wiring patterns by which the branch wiring patterns can be connected to locations other than those of the main wiring patterns. In other words, even if electrodes are concentrated on one side of a semiconductor chip, etc., the main wiring patterns connected to the one side of the electrodes are branched by the branch wiring patterns and are dispersed to the other locations. Also, the contact probe main body and the contact probe branch portion are integrally formed. Therefore, there is an advantage where the both the contact probe main body and the contact probe branch portion can be formed with equivalent high dimensional accuracy with minimal positional shifting in the main wiring patterns and the branch wiring patterns.
According to a seventh aspect of the present invention, there is provided the probe device of the sixth aspect, further including a wiring substrate having a plurality of substrate side wiring patterns respectively connected to middle portions or rear end portions of the main wiring patterns and the branch wiring patterns; and support members for supporting respective front end portions of the main wiring patterns.
According to the above-described probe device, the substrate side wiring patterns respectively connected to the main wiring patterns and the branch wiring patterns in the contact probe according to the sixth aspect, are formed at the wiring substrate. Therefore, the main wiring patterns are divided by the branch wiring patterns by which the substrate side wiring patterns connected thereto are also divided and are formed at separate locations and the arrangement space is wide and can be set with a high degree of freedom.
According to an eighth aspect of the present invention, there is provided the probe device of the seventh aspect, wherein the wiring substrate is provided with a rectangular opening for arranging the contact probe, a plurality of the contact pins of the contact probe are arranged along a diagonal line of the rectangular opening and the contact probe main body and the contact probe branch portion are respectively distributed to two sides of the rectangular opening opposed to the diagonal line; and wherein the main wiring patterns and the branch wiring patterns are respectively connected to the substrate side wiring patterns at the two sides of the rectangular opening.
According to the above-described probe device, the front end portions of the contact probe are arranged along the diagonal line of the rectangular opening. Therefore, an object of measurement such as an IC, etc. having electrodes which are particularly concentrated on one side can be arranged along the diagonal line. Therefore, the front end portions are correspondingly brought into contact with the one side of the electrodes. Then, the contact probe main body and the contact probe branch portion are distributed to left and right at the two sides of the rectangular opening and the main wiring patterns and the branch wiring patterns are separately connected to the substrate side wiring patterns at the two sides. Therefore, the wiring patterns concentrated on the one side of the electrodes of an IC, etc. can be distributed to left and right by which a number of wirings can be divided and arranged to two sides without concentrating on one side of the rectangular opening.
According to a ninth aspect of the present invention, there is provided the probe device of the seventh aspect, wherein the substrate side wiring patterns are respectively formed on a front face and a back face of the wiring substrate; wherein the contact probe main body and the contact probe branch portion are respectively distributed to the front face and the back face of the wiring substrate by folding a portion of either one thereof; and wherein the main wiring patterns and the branch wiring patterns are respectively connected to the substrate side wiring patterns at the two sides of the rectangular opening.
According to the above-described probe device, by folding, etc. the contact probe main body and the contact probe branch portion which are of a film-like shape and formed integrally with each other, are distributed to the front surface and the back face of the wiring substrate. Therefore, the main wiring patterns and the branch wiring patterns can be separately connected to the substrate side wiring patterns on two faces of the substrate. In this way, connection is facilitated by a doubled arrangement space of the substrate side wiring patterns without concentrating the wirings on one face of the wiring substrate.
According to a tenth aspect of the present invention, there is provided the probe device of the first aspect, the contact probe further including a contact probe main body including the wiring patterns disposed as a plurality main wiring patterns; and at least one of branch wiring plate connected to the contact probe main body by attaching a portion of the branch wiring plate to the contact probe main body, and including a plurality of branch wiring patterns; wherein the branch wiring patterns are each connected to portions of the plurality of main wiring patterns.
The above-described probe device includes the contact probe main body where the main wiring patterns are formed and the branch wiring plate connected to the contact probe main body. The branch wiring patterns connected to the main wiring patterns are formed at the branch wiring plate. Therefore, portions of the main wiring patterns are distributed to the branch wiring patterns by which the branch wiring patterns can be connected to locations other than those of the main wiring patterns. In other words, even if electrodes are concentrated on one side of a semiconductor chip, etc., the main wiring patterns connected to the one side of the electrodes, are branched and divided by the branch wiring patterns and are connected to other locations.
According to an eleventh aspect of the present invention, there is provided a probe device of the tenth aspect, further including a wiring substrate having a plurality of substrate side wiring patterns respectively connected to middle portions or rear end portions of the main wiring patterns and the branch wiring patterns; and supporting members for supporting the respective front end portions of the main wiring patterns; wherein the substrate side wiring patterns are respectively formed on a front face and a back face of the wiring substrate; wherein the contact probe main body and the branch wiring plate are respectively distributed to the front face and the back face of the wiring substrate; and wherein the main wiring patterns and the branch wiring patterns are respectively connected to the substrate side wiring patterns at the two sides of the rectangular opening.
According to the above-described probe device, the substrate side wiring patterns respectively connected to the main wiring patterns and the branch wiring patterns in the contact probe according to the tenth aspect of the present invention, are formed on the wiring substrate. Accordingly, the main wiring patterns are divided by the branch wiring patterns by which the substrate side wiring patterns connected thereto are also divided and are formed at separate locations, the arrangement space is wide and is set with a higher degree of freedom. Particularly, according to the above-described probe device, the contact probe main body and the branch wiring plate are distributed to the surface and the back face of the wiring substrate and the main wiring patterns and the branch wiring patterns can separately be connected to the substrate side wiring patterns at two faces of the surface and the back face of the wiring substrate. In this way, connection is facilitated by the doubled arrangement space of the substrate side wiring patterns without concentrating the wirings on one face of the wiring substrate.
According to a twelfth aspect of the present invention, there is provided a contact probe including a first contact probe including a first film, and a plurality of first wiring patterns formed on the first film, each first wiring pattern having a front end portion projecting from the first film so as to form contact pins; and a second contact probe connected to the first contact probe including a second film, and a plurality of second wiring patterns formed on the second film; wherein the plurality of second wiring patterns are connected to the plurality of first wiring patterns, and the second contact probe is formed separately from the first contact probe.
According to the above-described contact probe, the first contact probe and the second contact probe are formed by separate steps and thereafter, they are connected to each other such that the wiring patterns are connected.
According to a thirteenth aspect of the present invention, there is provided the contact probe of the twelfth aspect, wherein the plurality of first wiring patterns are densely formed, the plurality of second wiring patterns are densely formed at a vicinity of the connection to the plurality of first wiring patterns, and the plurality of second wiring patterns are coarsely formed at a position remote from the vicinity of the of the connection to the plurality of first wiring patterns.
According to a fourteenth aspect of the present invention, there is provided the contact probe of the twelfth aspect, wherein the plurality of first wiring patterns are formed densely at front end portions thereof and are coarsely formed at rear end portions thereof, and the plurality of second wiring patterns are coarsely formed and connected to the first wiring patterns at the rear end portions thereof.
According to the above-described contact probe, the first contact probe and the second contact probe are connected to each other where the wiring patterns of both of probes coarsely formed.
According to a fifteenth aspect of the present invention, there is provided the contact probe of the twelfth aspect, wherein an area of the first contact probe is configured to be smaller than an area of the second contact probe.
According to the above-described contact probe, the occupied area of the first contact probe where the wiring patterns are formed densely, is made smaller. Accordingly, an amount of yield at that portion is increased by decreasing the area where the densely formed expensive wiring patterns are present. Accordingly, fabrication cost of the contact probe formed by connecting the first contact probe and the second contact probe can be reduced.
According to a sixteenth aspect of the present invention, there is provided the contact probe of the twelfth aspect, further including an anisotropic conductive tape connecting the first contact probe and the second contact probe such that a face of the first contact probe where the plurality of first wiring patterns are formed is opposed to a face of the second contact probe where the plurality of second wiring patterns are formed.
According to the above-described contact probe, the first wiring pattern and the second wiring pattern are connected to each other by the anisotropic conductive tape. Therefore, the degree of allowance with respect to positional shift between the both wiring patterns is increased and positional matching is facilitated.
According to a seventeenth aspect of the present invention, there is provided the probe device of the first aspect, further including a plurality of the contact probes arranged such that axial lines of the contact pins are substantially vertical to a contact face of an object of measurement, and the plurality of contact probes are parallelly disposed so as to provide spaces between respective faces of the films of the plurality of contact probes.
According to an eighteenth aspect of the present invention, there is provided the probe device of seventeenth aspect, wherein a direction of bending of the contact pins of the plurality of the contact probes when a buckling load is applied is configured to be substantially constant.
According to the above-described probe device, when the contact pin is bent by receiving a buckling load in the overdriving operation, the direction of bending stays substantially constant. Therefore, contiguous ones of the contact pins are not erroneously brought into contact with each other.
According to a nineteenth aspect of the present invention, there is provided the probe device of the eighteenth aspect, wherein a position of buckling points in axial line directions of the contact pins of the plurality of the contact probes is configured to be substantially constant.
According to the above-described probe device, when the contact pin is bent, the position of a buckling point of the contact pin stays substantially constant. Therefore, contiguous ones of the contact pins are not erroneously brought into contact with each other.
According to a twentieth aspect of the present invention, there is provided the probe device of the eighteenth aspect, further including a metal film disposed on a back side the contact pins of the plurality of the contact probes at a specified position in an axial line direction, and which is subjected to a half-etching treatment.
According to the above-described probe device, the half-etching treatment is performed at a predetermined position of the metal film by a predetermined amount. In this way, the direction of bending and the position of bending the contact pin can be made constant. Furthermore, compared to the probe which is not subjected to the half-etching treatment, the contact probe of the present invention is liable to be bent by a smaller buckling load. Therefore, contact of a total of long and short pins with respect to the terminals can be ensured. In this case, a distortion caused in the contact pin in the overdriving operation, is shifted to the location of the half-etching treatment and occurrence of buckling (bending) at locations other than the portions can be prevented. Furthermore, if the contact pin per se is subjected to the half-etching treatment, the strength is weakened and the contact pin may be broken, however, there is no concern in the present invention.